Kevin Pietersen took a major step towards proving his fitness for the third Ashes Test at Old Trafford as Lancashire dismissed Australian suspicions of an ugly-looking pitch.

Pietersen, an injury doubt since suffering a calf strain during the second Test at Lord's, went through a series of exercises with Craig de Weymarn, England's head physio, on the outfield, either side of batting in the nets.

England will not make a final decision until evening, with James Taylor staying with the squad as batting cover. But all the indications are that Pietersen will play in an unchanged top seven.

The make-up of England's bowling attack is much more uncertain and the sight of a cracked pitch with unsightly bare patches two days out from the match provoked further discussion about the possibility of Monty Panesar being selected alongside Graeme Swann as a second specialist spinner.

This is the first Test at Old Trafford, where Panesar has enjoyed considerable success in the past, since the square was turned 90 degrees as part of the ground's redevelopment. "It looks a little bit interesting," said Australia's opener Chris Rogers. "There's a few cracks there already – it'll be interesting to see how it plays; it's quite hard."

Lancashire's groundstaff mowed and brushed the pitch after removing the covers following a lunchtime shower, watched by Chris Wood, the pitches consultant of the England and Wales Cricket Board. But the county's cricket director, Mike Watkinson, said that neither the cracks nor the bare patches – the legacy of a recent Twenty20 fixture between Lancashire and Leicestershire – were a cause for concern, reiterating his confidence that "it will be a good pitch, along the lines of the pitches we've had in the past for Tests here".

Australia have a fresh injury worry over Steve Smith, their leg-spinning all-rounder who would surely relish the opportunity to bowl at the ground which was always Shane Warne's favourite in England after his spectacular first delivery against Mike Gatting in 1993. Smith missed training with a back problem although Rogers remained hopeful that he would be "good to go" by Thursday. David Warner played a full part in practice to reinforce the general expectation he will come into Australia's middle order, probably in place of Phil Hughes, and Rogers believes that after blasting a big century for the A team in South Africa last week, he could offer the same sort of threat as Adam Gilchrist in previous series.

"Davey brings a lot of energy to the group always," he added. "He's just one of those guys, he goes at 100 miles an hour. It's fantastic to see him get runs, he's such a destructive player that if he bats for a while he could put some real pressure on England. He's one of those the opposition know they have to get out quickly. If he bats for a while he can take the game away, like a Gilchrist used to do.".